Layer pad

ABSTRACT

A layer pad ( 10 ) comprises a substantially flat sheet ( 12 ) having first and second opposite substantially planar faces ( 14, 16 ). The layer pad ( 10 ) further includes at least one raised formation ( 18 ) on at least one of the faces ( 14, 16 ).

BACKGROUND OF THE INVENTION

This invention relates to pads. More particularly, but not exclusively,this invention relates to layer pads for use on layers of a load.Embodiments of this invention relate to slip sheets for use betweenlayers of a load.

Layer pads are used between layers of loads on pallets to hold the lowerlayer in place and provide a base for the upper layer. One example of alayer pad is disclosed in EP1833728A. It has been discovered, however,that some prior art layer pads have a tendency to warp after having beenmanufactured.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of this invention, there is provided a padcomprising a substantially flat sheet having first and second oppositesubstantially planar faces, wherein the pad further includes at leastone raised formation on at least one of the faces.

The pad may be in the form of a layer pad for use on a layer of articlesforming a load.

In one embodiment, the pad may include a respective raised formation oneach of the first and second faces. The pad may include a plurality ofthe raised formations on each of the first and second faces. The, oreach, raised formation may be conical or frustoconical in shape.

The thickness of the pad at regions at which one of the raisedformations is present may be substantially 30% thicker than regions ofthe pad devoid of the aforesaid raised formations.

The, or each, raised formation may have a main region extending from thefirst or second face. The, or each, raised formation may further includean apex region spaced from the respective first or second face.

The apex region may be substantially planar. Each of the main regionsmay taper inwardly from the respective face to the apex region.

A plurality of rows of the raised formations may be provided on the, oreach, face. Where the raised formations are provided on each of thefirst and second faces, the raised formations on the first face may bealigned with the raised formations on the second face. Each apex regionmay be substantially planar.

Each raised formation may have substantially the same height as the, oreach, other to raised formation. Thus, the apex regions of the raisedformations on each face define a respective plane.

The sheet may be substantially rectangular. The pad may have marginalportions on the sheet. The marginal portions may extend around thesheet.

The sheet may have corner regions. The marginal portions may extendaround the corner regions. The marginal portions may be curved aroundthe corner regions.

The marginal portions may have outer edges. The marginal portions maycomprise corrugations, which may extend perpendicular from the outeredges. The corrugations may merge into the sheet.

According to another aspect of this invention, there is provided amethod of forming a pad as described above, wherein said methodcomprises providing a mould having at least one injection port for amoulding material, said mould defining a mould space having a relativelynarrow region and at least one relatively wide region, injecting themoulding material into the mould space to fill the relatively narrowregion and the relatively wide region, allowing the moulding material tocure and thereafter releasing the so formed pad from the mould.

The moulding material may comprise a molten plastics material.

The mould space may have a plurality of relatively wide regions withinthe relatively narrow region. The mould space may have first and secondopposite sides and a respective wide region on each side.

The mould space may have first and second opposite sides and a pluralityof respective wide regions on each side. The mould space may includefirst and second mould parts to provide the first and second oppositesides of the mould space respectively.

The first mould part may define a recess to provide the relatively wideregion in the mould space. The first mould part may define a pluralityof the aforesaid recesses. The second mould part may define a recess toprovide the relatively wide region in the mould space. The second mouldpart may define a plurality of the aforesaid recesses.

Each of the first and second mould parts may define a plurality of therecesses to provide a plurality of relatively wide regions on each sideof the mould space.

The first mould part may comprise a substantially planar region. Thesecond mould part may comprise a substantially planar region

Each of the first and second mould parts may define a respective recessto provide the respective relatively wide regions on each side of themould space.

The, or each relatively wide region may be substantially frustoconicalin shape. The, or each, recess may be substantially frustoconical inshape.

A plurality of rows of the relatively wide regions may be provided onthe, or each, side of the mould space. Where the relatively wide regionsare provided on each of the first and second sides of the mould space,the relatively wide regions on the first side may be aligned with therelatively wide regions on the second side.

A plurality of rows of the recesses may be defined in the, or each,mould part. Where the recesses are defined in each of the first andsecond mould parts, the recesses defined the first mould part may bealigned with the recesses defined in the second mould part.

The mould space may be substantially rectangular. The pad may have oneor more marginal portions on the sheet. The, or each, marginal portionmay extend around the sheet.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

An embodiment of the invention will now be described by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view from above of a pad;

FIG. 2 is a perspective view from below of the pad shown in FIG. 1;

FIG. 3 is a view along the line II-II in FIG. 1; and

FIG. 4 is a schematic sectional side view of a mould for forming the padshown in FIGS. 1, 2 and 3.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1, 2 and 3 show a pad in the form of a layer pad 10, which isdisposed between layers of a load (not shown), for example bottles. Theload may be arranged in the layers on a pallet.

The layer pad 10 comprises a substantially flat sheet 12 having firstand second opposite faces 14, 16, which are identical to each other. Thefaces 14, 16 are substantially planar. As shown in FIG. 1, the layer pad10 is substantially rectangular.

The layer pad 10 further include a plurality of raised formations 18 oneach of the first and second faces 14, 16. Each raised formation 18 onthe first face 14 is substantially aligned with a respective one of theraised formations 18 on the second face 16. The raised formations 18 areof a frustoconical shape comprising a shallow tapering main region 20and a substantially planar apex region 22. A planar region 14A of thefirst face 14 is provided between the raised formations 18 on the firstface 14. A planar region 16A of the second face 16 is provided betweenthe raised formations of the second face 16.

The aligned raised formations 18 increase the thickness of the sheet 12by about 30% between the apex regions 22 compared to the thickness ofthe sheet 12 at the planar region 12A.

The main region 20 of each raised formation extends outwardly from therespective first or second face 14, 16 to the apex region 22. Each mainregion 20 tapers inwardly towards the apex region 22. The apex region 22is substantially circular.

Each of the raised formations 18 may have substantially the same heightas each of the other raised formations 18. Thus, the apex regions 22 oneach of the first and second faces 14, 16 define a respective plane.

The raised formations 18 on the first face 14 are the same as the raisedformations on the second face 16. The raised formations 20 are arrangedin substantially identical regular arrays, as shown in FIGS. 1 and 2, onboth of the first and second faces 14, 16.

The layer pad 10 has marginal portions 24, which extend around thesubstantially flat sheet 12. The sheet 12 has corner regions 26, and themarginal portions 24 extend around the corner regions 26. The cornerregions 26 are curved and, as a result, the marginal portions 24 curvearound the corner regions 26. The marginal portions 24 have an outeredge 25 and corrugations 28 which extend inwardly from the outer edge 25to merge with the sheet 12.

FIG. 4 shows a mould 30 for manufacturing the layer pad 10. The mould 30comprises a first and second mould parts 32, 33, each having a planarregion comprising a planar inner surface 34 and a plurality of recesses36. Each recess 36 is of a substantially frustoconical shape having amain recess region 38 and an apex region 40. The apex region 40 issubstantially circular.

An injection port 42 extends through the apex region 40 of the recess 36in the first and second mould parts 32, 33. The first and second mouldparts 32, 33 can be arranged in a moulding position shown in FIG. 4 todefine a mould space 43 therebetween. The mould space 43 has arelatively narrow region 43A between the opposite planar surfaces 34,and relatively wider regions 43B between the opposite recesses 36.

If desired a respective injection port 42 may be provided in each of theapex regions 40 of all the recesses 36 of the first and second mouldparts 32, 33. A respective conduit 44 extends to each injection port 42through which a moulding material, such as a molten plastics material,is injected into the mould space 43.

In order to form the layer pad 10, the mould parts 32, 33 are secured toeach other by suitable means known in the art of injection moulding inthe position shown FIG. 4 to define the mould space therebetween. Asuitable moulding material, such as a molten plastics material, is theninjected into the mould space via all the injection ports 42 in each ofthe mould parts 32, 33. When the injection is completed, the mouldingmaterial is allowed to cure, and the layer pad 10 is then removed fromthe mould.

The provision of the raised formations 18 on the planar surfaces 12A ofthe substantially flat sheet 12 provides the advantage of the embodimentdescribed herein that it helps prevent warping of the sheet 12 when thelayer pad 10 is removed from the mould.

The injection of the moulding material into the mould 30 at the apexregions 40 of the recesses 36 provides the advantage in the embodimentdescribed herein that the moulding material enters the mould 30 in acondition that does not induce stress in the moulding. It is believedthat the provision of the injection ports 42 at the recesses 36 reducesthe pressure at the injection ports during the injection of the mouldingmaterial.

The reduction in pressure has the effect of reducing the stressexperienced by the material, thereby allowing uniform crystallisation.As a result of this lack of stress, there is little or no tendency ofthe layer pad 10 to warp when it is removed from the mould 30.

There is thus described a layer pad 10 and a method of manufacturing thelayer pad 10 that provides the advantage that the layer pad 10 does nothave a tendency to warp when the method of manufacture is complete.

Various modifications can be made without departing from the scope ofthe invention, for example, the arrangement and amount of the raisedformations 18 on the sheet 12 can be different from the arrangement andamount shown in FIGS. 1 and 2. If desired, the raised formations 18 canbe provided on only one of the faces 14, 16 of the sheet 12. Theinjection ports 42 can be provided at only some of the recesses 36. Ifdesired, the injection ports 42 could be provided at some or all of therecesses 36 in only one of the first and second mould parts 32, 33.

The invention claimed is:
 1. A pad comprising a substantially flat sheethaving first and second opposite substantially planar faces, wherein thepad further includes a plurality of raised formations on each of thefaces, each raised formation being conical or frustoconical in shape,and each raised formation having a main region extending from the firstor second face, and each raised formation having an apex region spacedfrom the respective first or second face, wherein the thickness of thepad between the apex regions is about 30% thicker than regions of thepad devoid of the aforesaid raised formations.
 2. A pad according toclaim 1, wherein each apex region is substantially planar, and the mainregion of the, or each, raised formation tapers inwardly from the faceto the apex region.
 3. A pad according to claim 1, wherein a pluralityof rows of the raised formations are provided on the, or each, face, andthe raised formations on the first face are aligned with the raisedformations on the second face.
 4. A pad according to claim 1, whereinthe sheet is substantially rectangular, and the pad has marginalportions on the sheet, the marginal portions extending around the sheet.5. A pad according to claim 4, wherein the sheet has corner regions, themarginal portions extending around the corner regions.
 6. A padaccording to claim 5, wherein the marginal portions are curved aroundthe corner regions.
 7. A pad according to claim 4, wherein the marginalportions have outer edges, and the marginal portions comprisecorrugations extending perpendicularly from the outer edges, thecorrugations merging into the sheet.